First of all, I’m not going to answer any of the points made on the above page.

But I will say this. Helmets ought not to be encouraged by cycling commuting because they are a HUGE waste of money. If half the cyclists who ride their bikes once or more a year spent their “helmet money” on infrastructure in one year we’d have Portland in all of our major cities. In fact, he actually conceeded that if we had better infrastructure then we would have less injuries than we do now with helmets.

Well, I have been asked to do it, and now I will, I’m going after serious injuries that were prevented by helmets.

First let’s talk claims.

You can quote me on this. If Mitt Romney wins the election, and he wants to get his scissors out, he can start by cutting the National Highway Traffic Safety Administration (NHTSA). Not to digress, but they are a number of reasons that this is a piece of shit organization and being useless is not the only one. They are also a sleeper protectionist organization masquerading (and doing a shit job) as a safety agency. See wikipedia for details.

However, they did me a favor by putting out a juicy and crazy “Traffic Safety Facts” page:

“The estimated annual cost of bicycle‐related injuries and deaths (for all ages) is $8 billion.”
First of all, note the use of the word “estimated”. See Mitch Hedberg for details on how they “estimate” things. 🙂
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This would be significant cost savings!

Imagine a magical alternative place, similar to the US, where they actually did have a helmet law. You’d expect the health care spending to go down, after such a law, or at least remain stable. Yes.

Please look on page two at either graph. Note the lines for Australia. Do you see the big dip on the left graph? Haha, that’s NOT Australia and it’s not during the 90’s but it is the kind of dip that I’d expect if we had a few billion dollars cost savings in health car. I would not expect the spending to go up but that’s exactly what it did.

Why no change?

Because helmets don’t save any significant amount of money in health care costs.

This leads us to this excellent analysis of the effects of helmets on injury rates:

“A careful look at the study shows there appears to be a significant benefit only over a short-period of time, across the few months where the [mandatory helmet] law is passed. While beyond that the helmet law has managed to turn a decreasing head injury rate into an increasing head injury rate (fig 3)…So what is happening?”

The study mentions regression to the mean without being explicit:

“Another possibility is that injury rates just happened co-incidentally to be at a high prior to the law, and that the law has had little causal effect.”

I agree that this has to be a big factor. It almost always is when you have data that tend to be consistent overall but will fluctuate over time.

Conclusion:

“That means, so far as the study is accurate, that beyond a short-period, the study actually shows an apparent detrimental impact on safety in terms of head injury rates,”

While “correlation does not always indicate causation” sometimes it does.

Also, before you get causation you do need to have correlation. Since we don’t have it, it’s safe to say that helmets are useless, overall, for preventing injuries and for reducing health care costs.